They pinned him Down Under.

A Virgin Australia flight had to be turned back after a passenger “suddenly went bananas” — stripping off his clothes and knocking over a flight attendant while running naked through the aisle.

The “disruptive passenger” was eventually arrested — with a wild photo showing him being pinned down face-first by someone with a foot on his back near his still-exposed naked butt.

The unidentified man stripped off Monday soon after flight VA696 left Perth for Melbourne.

He “suddenly went bananas, running up and down the aisle and bashing on the cockpit door,” knocking over a flight crew member, another passenger told Australian radio station 3AW.

“Two air marshals had to restrain and handcuff the individual until they landed,” the anonymous caller said.

The plane was forced to turn back to Perth, where it was met by cops who arrested the “disruptive passenger,” Virgin Australia said.

Australian Federal Police confirmed that “officers arrested a man after he allegedly ran naked through the aircraft mid-flight and knocked a crew member to the floor.”

The unidentified Virgin staffer was not injured, according to the Australian Broadcasting Corp.

“The man was transferred to hospital for assessment, where he remains,” police said.

It was not clear how or where on the plane the passenger removed his clothes.

He is expected to appear before the court on June 14. It is not clear what charges he might face.

Passengers were already frustrated because the flight had been delayed by 90 minutes even before the doomed take-off, according to the passenger who called 3AW.

While some travelers were able to catch another Melbourne-bound flight, others were left “stranded,” they lamented.

Virgin Australia apologized to the “guests impacted” – adding that the safety of passengers and crew remained its top priority. 

With Post wires